AP® Biology Course and Exam Description
AP® Biology is one of the most popular courses within the gamut of AP courses. It covers fundamental concepts in Biology at the foundational level and teaches students critical thinking through core science practices. While the course may be vast and challenging, you will be able to build a strong foundation in Biology, which can set you up for success at the college level.
Understanding what to expect as a student of AP Biology is the first step to a good score. In this AP Biology course and exam description, we’ll take a look at the AP Biology course outline as well as the weightage of each unit in the final exam so you can be best prepared. We’ll also identify AP Biology’s key concepts and what you’ll learn from each of them. Let’s dive right in!
AP Biology Units, Topics, and Key Concepts
In order to understand what you will learn in this course, it’s essential to know the outline of the course itself. It will help you identify if you are ready to take AP Biology.
The course is made up of two primary sections — Science Practices and Course Content. As you progress through the course, you will learn essential science practices through the course content or lessons, so the two are intertwined from the very beginning and both are equally important for building a solid foundation in biology.
The course content is broken down into units, which are further broken down into smaller topics to make learning easy. Each of these units is based on the 4 Big Ideas, known as the essential biological concepts critical to a strong foundation in biology. The exam itself is made up of 60 multiple choice questions (MCQs) and 6 free-response questions (FRQs) from these units with varying weightages. You can read more about the exam format from our AP Biology Exam Format.
What Are the AP Biology Science Practices?
Science Practices are skills vital to the study and practice of biology. They promote critical thinking and analysis, which are necessary for further studies in biology and are also key to doing well on the exam. You will be expected to develop and master these skills throughout the AP Biology course. In addition, each unit within the course will encourage learning a particular set of science practices.
There are six science practices in AP Biology that you will master by the end of the course. Below is a detailed list of these science practices and the skills they will teach you.
- Concept Explanation
This science practice aims at developing your ability to explain concepts, models, and processes of biology that can be seen in written format.Skills you will learn:
- Describe biological concepts and processes – Describe traits, characteristics, elements, etc., in a particular concept and describe structures and functions within a process.
- Explain biological concepts and processes – Explain concepts, steps of a process, the relationship between structures and their functions, and trends in a system.
- Explain applied biological models, concepts, and processes in a particular context – Explain how biological models, concepts, and processes apply in the real world.
- Visual Representations
Visual representations are an essential tool in biology, especially when learning and exploring new concepts. This science practice will teach you how to create, use, and analyze visual representations.Skills you will learn:
- Describe visually represented concepts, processes, and models – Describe characteristics, patterns, and trends.
- Explain relationships between characteristics in visually represented concepts, processes, and models – Explain concepts and compare and predict patterns/trends in a representation.
- Correlate concepts and processes in a representation to principles and theories in biology – Develop conclusions based on the concepts in a representation.
- Showcase relationships in a biological model – Representation of relationships using mathematical models, diagrams, and flowcharts.
- Questions and Methods
Questioning natural phenomena is a critical scientific practice that will help further your understanding of biological concepts. You will learn to identify possible errors in experiments or data sets and make revisions to gain more accurate results.Skills you will learn:
- Identify or come up with valid, testable questions from the provided data – Make and evaluate inquiries related to natural phenomena from a given set of data by experimentation, research, and discussion.
- Identify null or alternative hypotheses and predict experimental results
- Identify experimental procedures related to the question – Identify dependent and independent variables, controls, and justify the usage of these controls.
- Gather data and state observations from results or laboratory setups – this is only assessed during your labs and you will not be tested on this in the actual AP Biology exam
- Propose a new experiment – Evaluate the evidence and methods of a particular experiment and suggest a new experiment based on your questioning of natural phenomena and findings from the current experiment.
- Representing and Describing Data
Communicating the data you have collected from an experiment is an important skill that any biologist must acquire. You will learn how to create graphs and understand which type of graph to use for any given data set.Skills you will learn:
- Plot and construct a graph or chart – Learn how to construct line graphs, histograms, pie charts, box and whisker plots, dual y-axis graphs, and log Y graphs. You will be expected to know graph plotting techniques and design basics such as understanding how to label axes, orient variables on the graph, scale the graph, and even how to plot your units.
- Describe data showcased in a graph or table – Identify data points from a table or chart, describe trends and patterns, and explain how variables are related in a graph or chart.
- Statistical Tests and Data Analysis
You will learn to use mathematics to analyze data, solve problems, make predictions about natural phenomena, and showcase processes symbolically.Skills you will learn:
- Use mathematical formulas to perform calculations – Calculations will include mean of a data set, rate calculations, rate of a reaction, ratios, and percentage of change, and equations in the AP Biology curriculum (these will be found in your formula sheet on exam day).
- Confidence intervals and error bars – Learn to draw standard error bars and error bars for the 95% confidence interval to determine the difference between sample means, if any.
- Chi-square hypothesis testing – Learn how to determine the chi-square value and the p-value of a data set and compare the two to draw conclusions about the given experiment.
- Make predictions or evaluate hypotheses using data – This includes rejecting or not rejecting the null hypothesis and supporting or rejecting the alternative hypothesis.
- Argumentation
Engaging in evidence-based scientific argumentation is of the most important skills any scientist could acquire. You will be expected to make sound arguments based on evidence from g biological processes and phenomena.Skills you will learn:
- Making a claim – Learn how to describe data shown in a graph or table and draw conclusions from the experimental results.
- Supporting claims using evidence – Use biological concepts, principles, data, and processes to justify a certain claim.
- Reasoning – Understand how to use biological theories in justifying a claim by relating it to the evidence from an experiment.
- Explaining relationships – Learn how to explain the relationship between results and broader biological theories, concepts, and processes.
- Predict causes and effects – Describe the impact of disruption to biological components in a particular system using biological concepts, processes, visual representations, and data
This wraps up our sneak peek into the science practices taught in AP Biology. Now let’s break down the AP Biology topics starting with the 4 Big Ideas.
AP Biology’s 4 Big Ideas
The big ideas are nothing but the themes that will be explored through the AP Biology topics. They provide the foundation upon which the course is structured. These big ideas are interwoven into the multiple units of the course because they apply to various contexts. Let’s take a look at each of these big ideas.- Evolution - The process that drives diversity and unity of life.
Evolution is the change of gene frequencies in a population over time and leads to biodiversity within and among species. Charles Darwin’s theory explains how populations evolve through accumulating changes in their genes, won through the process of natural selection. Darwin observed that individuals with certain traits that benefit environmental conditions were able to survive and reproduce at higher rates, passing their genetic material on to future generations. With each new generation, the gene pool became more diverse.
In addition to natural selection, gene pools can be altered by natural catastrophes and human-induced events. As the environment continues to change, organisms keep evolving with it, forming a vibrant and diverse ecosystem.
The units you will study that further elaborate this Big Idea are: Cell Structure and Function, Heredity, Natural Selection, and Ecology.
- Energetics - Biological systems depend on energy and molecules to grow, reproduce, and maintain homeostasis.
Living systems need energy and matter to facilitate growth, reproduction, and survival. They employ various methods to attain, use, and store this energy. Given that natural systems are interdependent and rely heavily on energy, any deficiencies in energy sources could have detrimental effects on populations and ecosystems.
The units you will study that further elaborate this theme are: Chemistry of Life, Cell Structure and Function, Cellular Energetics, Cell Communication and Cell Cycle, and Ecology.
- Information Storage And Transmission - Living systems store, retrieve, transmit, and respond to information essential to various life processes.
Genetic information is a repository of instructions necessary for the survival, growth, and reproduction of an organism. This information repository is stored in DNA, which is passed on from parent to offspring to promote the continuity of life. On the other hand, non-inheritable information influences behavior between cells, organisms, and populations. This reception of information is essential for evolution and natural selection.
The units you will study that further elaborate this theme are: Chemistry of Life, Cell Communication and Cell Cycle, Heredity, Gene Expression and Regulation, and Ecology.
- Systems Interactions - Biological systems interact with each other exhibiting complex properties.
All biological systems at the molecular and ecosystem levels interact with each other. With this comes enhanced diversity, which enables better resiliency and the ability to withstand environmental changes.
The units you will study that further elaborate this theme are: Chemistry of Life, Cell Communication and Cell Cycle, Cellular Energies, Heredity, Natural Selection, and Ecology.
The Eight Units of AP® Biology & Their Topics
The AP Biology course outline shows that the course is divided into eight units. Each unit will focus on one or more of the 4 big ideas. These units are further broken down into several topics that enable the learning of specific content and scientific practices. In this AP Biology course and exam description, we’ll look at each of these eight units, their weightage in the final AP Biology exam, and their related topics.
Unit 1 – Chemistry of Life
(8–11% Exam Weighting | 5-7 Class Periods)
This unit explores the chemical nature of life. Studying this will equip you to understand and analyze the elements required for the existence of carbon-based natural systems. You will learn how water, acquiring energy, and the exchange of macromolecules are essential to the presence of living systems. Given that this unit is about the chemistry of life, you will also study chemical processes at the molecular level — like the conformations in which monomers bond to become polymers and their structures.
The big ideas explored in this unit:
- Big Idea 2: Energetics – The role of energy in synthesis and breakdown of polymers
- Big Idea 3: Information Storage & Transmission – The transmission of information between living systems to ensure survival
- Big Idea 4: Systems Interactions – The importance of the water’s polarity in living systems
| Topic | Objective | Suggested Science Practice |
|---|---|---|
| 1.1 Structure of Water and Hydrogen Bonding | Learn to explain how the polar nature of water is essential to living systems. | 2. Visual representations |
| 1.2 Elements of Life | Learn to describe and analyze the composition of macromolecules, primarily carbon and nitrogen-based macromolecules. | 2. Visual representations |
| 1.3 Introduction to Biological Macromolecules | Learn about the properties of monomers and identify the type of bonds that connect monomers in macromolecules. | 2. Visual representations |
| 1.4 Properties of Biological Macromolecules | Learn about the structure and function of polymers and they are affected by the arrangement of monomer components. . Your study will focus primarily on nucleic acids, proteins, complex carbohydrates, and lipids. | 1. Concept Explanation |
| 1.5 Structure and Function of Biological Macromolecules | Analyze and explain the effect of a change in subunits of a polymer on the structure or function of macromolecules. | 6. Argumentation |
| 1.6 Nucleic Acids | Learn about the relationship and differences between DNA and RNA molecules. | 2. Visual Representations |
If you would like an in-depth study of the components of Unit 1, you can read our article on AP Biology Unit 1: Chemistry of Life.
Unit 2 – Cell Structure and Function
(10–13% Exam Weighting | 11–13 Class Periods)
As you know, the cell is the most basic unit of life. Therefore, as a student of biology, you must learn about the inner workings of a cell — its structure and function. In this unit, you will learn about the cell membrane, homeostasis, organelles, and cellular products. You will also study the relationship between organelles and cellular components.
The big ideas explored in this unit:
- Big Idea 1: Evolution – The eukaryotic cell’s origin
- Big Idea 2: Energetics – The advantages and disadvantages of cellular compartmentalization and the role of transport mechanisms involving the cell membrane in the conservation of energy.
- Big Idea 4: Systems Interactions – The effect of the presence or absence of subcellular components on living systems.
| Topic | Objective | Suggested Science Practice |
|---|---|---|
| 2.1 Cell Structure: Subcellular Components | Learn about the structure and function of subcellular components and organelles such as the ribosomes, endoplasmic reticulum, Golgi complex, mitochondria, lysosomes, vacuoles, and chloroplasts. | 1. Concept Explanation |
| 2.2 Cell Function & Structure | Learn how subcellular components and organelles function within a cell. Learn about the structural features of a cell that aid in its functioning. | 6. Argumentation |
| 2.3 Cell Size | Learn about the exchange of materials between cells and the environment and the effect of surface-area-to-volume ratios on this exchange. Learn how structures and strategies contribute to the exchange of molecules between cells and the environment. | 2. Visual Representations 5. Statistical Tests & Data Analysis |
| 2.4 Plasma Membranes | Learn to describe how membrane components work to maintain the internal environment of a cell. Learn to describe the Fluid Mosaic model of cell membranes. | 2. Visual Representations |
| 2.5 Membrane Permeability | Learn how the structure of a cell membrane aids in selective permeability. Learn to describe how the cell wall affects cell function. | 3. Questions and Methods 5. Statistical Tests and Data Analysis |
| 2.6 Membrane Transport | Learn to describe the mechanisms used to maintain solute and water balance. Learn to describe the mechanisms used to move large molecules across the plasma membrane. | 3. Questions and Methods |
| 2.7 Facilitated Diffusion | Learn to justify how the structure of a molecule can affect its ability to travel across the plasma membrane. | 6. Argumentation |
| 2.8 Tonicity and Osmoregulation | Learn to explain the importance of osmoregulatory mechanisms. Learn to explain the relation between concentration gradients and the movement of molecules across membranes. | 4. Representing and Describing Data |
| 2.9 Mechanisms of Transport | Learn to describe how ions and other molecules get across membranes. | 1. Concept Explanation |
| 2.10 Cell Compartmentalization | Learn to describe the structures in the membrane of a eukaryotic cell. Explain how organelles contribute to compartmentalization of eukaryotic cell functions. | 6. Argumentation |
| 2.11 Origins of Cell Compartmentalization | Describe the similarities and differences between prokaryotic and eukaryotic cells. Learn to describe the relationship between endosymbiotic organelles and their free-living ancestors in terms of their function. | 6. Argumentation |
To learn more about this unit, check out our article AP Biology Unit 2: Cell Structure and Function.
Unit 3 – Cellular Energetics
(12–16% Exam Weighting | 14–17 Class Periods)
In continuation with the study of cells from Unit 2, in Unit 3 you will learn about cellular energetics. Living systems are composed of cells in a complex manner and require a steady inflow of energy. This unit will teach you how this energy is captured, stored, and used. The main processes you will study include photosynthesis and cellular respiration.
The big ideas explored in this unit:
- Big Idea 1: Energetics – The accumulation and usage of energy by a living system.
- Big Idea 4: Systems interactions – The usage or conservation of energy in relation to external stimuli.
| Topic | Objective | Science Practice |
|---|---|---|
| 3.1 Enzyme Structure | Learn how to describe and explain the properties of enzymes. | 1. Concept Explanation |
| 3.2 Enzyme Catalysis | Learn to explain how the rate of reactions is affected by enzymes. | 3. Questions and Methods |
| 3.3 Environmental Impacts on Enzyme Function | Learn to identify and explain how changes to the structure of an enzyme can affect its functioning. Learn to identify and explain how the environment within a cell affects enzyme activity. | 6. Argumentation |
| 3.4 Cellular Energy | Learn about the role of energy in living organisms and how to describe it. | 6. Argumentation |
| 3.5 Photosynthesis | Learn to describe the process of photosynthesis that various organisms employ to capture and retain energy. Learn to explain how energy from various sources of light is captured and transferred to molecules. | 6. Argumentation |
| 3.6 Cellular Respiration | Learn how to explain the various processes that organisms use to utilize the energy stored in macromolecules. Learn to explain how cells acquire energy from macromolecules to perform cellular functions. | 4. Representing and Describing Data |
| 3.7 Fitness | Learn to identify and explain the relationship between changes in the number and types of molecules in a cell and the ability of an organism to survive and reproduce. | 6. Argumentation |
While this is just an outline, we’ve also put together a detailed breakdown of this unit in our article AP Biology Unit 3 – Cellular Energetics.
Unit 4 – Cell Communication and Cell Cycle
(10–15% Exam Weighting | 9–11 Class Periods)
Transduction pathways enable cells to communicate. Cells can also receive and generate signals in response to environmental cues. As part of the cell cycle, cells can also coordinate growth mechanisms, replicating and regulating replications to enable continuity of life. In this unit, you will explore how cells use energy and information transmission to communicate and replicate.
The big ideas explored in this unit:
- Big Idea 2: Energetics – How do cells use energy to communicate with each other?
- Big Idea 3: Information storage and transformation – How the cell cycle helps with the retention of genetic information and why cells communicate with each other?
| Topic | Objective | Suggested Science Practice |
|---|---|---|
| 4.1 Cell Communication | Learn to describe how cells communicate with each other. Learn how to explain the ability of cells to communicate over short and long distances. | 1. Concept Explanation |
| 4.2 Introduction to Signal Transduction | Learn and describe the elements of a signal transduction pathway. Learn and describe the function of each element in the signal transduction pathway in inducing a cellular response. | 1. Concept Explanation |
| 4.3 Signal Transduction | Understand and describe how the environment affects cellular response. Learn to describe the various types of cellular responses made possible by transduction pathways. | 6. Argumentation |
| 4.4 Changes in Signal Transduction Pathways | Learn to explain possible changes in a communication pathway when the structure of a signaling molecule is affected. | 6. Argumentation |
| 4.5 Feedback | Learn to describe positive and negative feedback mechanisms. Learn how negative feedback affects homeostasis. Learn the effect of positive feedback on homeostasis. | 6. Argumentation |
| 4.6 Cell Cycle | Learn to describe the stages of the cell cycle. Learn about and explain the role of mitosis in the generational transmission of chromosomes. | 4. Representing and Describing Data 5. Statistical Tests and Data Analysis |
| 4.7 Regulation of Cell Cycle | Identify and describe the role of internal controls in regulating the progression of the cell cycle. Identify and describe how disruptions in the cell cycle may result in apoptosis. | 6. Argumentation |
To learn more about the concepts you will be introduced to in this unit, take a look at our article on AP Biology Unit 4 – Cell Communication and Cell Cycle will be perfect for you.
Unit 5 – Heredity
(8–11% Exam Weighting | 9–11 Class Periods)
This unit deals with the concept of heredity with a focus on the biological concepts and processes involved. You will learn about the storage and transmission of information from one generation to another through meiosis. Exposure to Mendel’s laws is also a key part of this unit wherein you will understand Mendelian and non-Mendelian patterns of inheritance.
The big ideas explored in this unit:
- Big Idea 1: Evolution – The influence of genetics on our understanding of evolution.
- Big Idea 3: Information Storage and Transmission – The importance of characteristics suppression from one generation to the next and arguing Mendel’s laws.
- Big Idea 4: Systems Interactions – Influence of the diversity of a species on inheritance.
| Topic | Objective | Suggested Science Practice |
|---|---|---|
| 5.1 Meiosis | Learn about the transmission of chromosomes from one generation to the next as a result of meiosis. Learn about and explain the similarities and differences between meiosis and mitosis. | 1. Concept Explanation |
| 5.2 Meiosis and Genetic Diversity | Learn and explain how meiosis generates genetic diversity. | 3. Questions and Methods |
| 5.3 Mendelian Genetics | Learn and argue the concept of common ancestry for all organisms as supported by various processes and features. Learn about the inheritance of traits according to Mendel’s laws. | 6. Argumentation 5. Statistical Tests and Data Analysis |
| 5.4 Non-Mendelian Genetics | Lean and explain how the patterns of trait inheritance can deviate from those predicted by Mendel’s laws. | 5. Statistical Tests and Data Analysis |
| 5.5 Environmental Effects on Phenotype | Learn and explain how changes in the environment can lead to phenotypic plasticity. | 1. Concept Explanation |
| 5.6 Chromosomal Inheritance | Learn and argue how genetic variation is generated by chromosomal inheritance via reproduction. | 6. Argumentation |
If you’re looking for a more detailed study guide of this unit, read our article AP Biology Unit 5 – Heredity.
Unit 6 – Gene Expression and Regulation
(12–16% Exam Weighting | 18–21 Class Periods)
In this unit, you will learn about nucleic acids and their importance to gene expression. A deep dive into DNA and RNA will also offer you a closer look at their structural differences. You will then learn how an individual’s genotype is reflected in that individual’s phenotype. In addition to this, the unit includes topics such as protein synthesis, regulation of gene expression, and cell specialization — all critical processes that ensure the survival of individuals.
The big ideas explored in this unit:
- Big Idea 3: Information Storage and Transmission – The relationship between gene regulation and the continuity of life and the diversification of genetic information from one generation to the next.
| Topic | Objective | Suggested Science Practice |
|---|---|---|
| 6.1 DNA & RNA Structure | Learn and describe the passing of hereditary information between generations. Learn about the characteristics that make DNA function as hereditary material. | 1. Concept Explanation |
| 6.2 Replication | Describe the mechanisms by which DNA replication ensures genetic information transmission from one generation to the next. | 2. Visual Representations |
| 6.3 Transcription and RNA Processing | Learn and describe how genetic information is transmitted from DNA to RNA to amino acids in a protein. | 2. Visual Representations |
| 6.4 Translation | Learn to explain how an organism’s phenotype is dependent on its genotype. | 6. Argumentation 2. Visual Representations |
| 6.5 Regulation of Gene Expression | Learn and describe how various interactions regulate gene expression. | 6. Argumentation |
| 6.6 Gene Expression and Cell Specialization | Learn and explain how the phenotype of an organism is directly affected by the binding of transcription factors to promoter regions. Explain how phenotypic differences in cells and organisms can occur due to the regulation of gene expression. | 6. Argumentation |
| 6.7 Mutations | Learn about the types of gene mutations. Explain the relationship between change in genotype and phenotype. Learn how changes in genotype affecting phenotype can cause variation that is subject to natural selection. | 2. Visual Representations 3. Questions and Methods |
| 6.8 Biotechnology | Learn and explain how DNA and RNA can be analyzed and manipulated when subject to various engineering techniques. | 6. Argumentation |
Want to plan your review of this unit better? Then study our unit guide on AP Biology Unit 6 – Gene Expression and Regulation.
Unit 7 – Natural Selection
(13–20% Exam Weighting | 20–23 Class Periods)
Natural selection is a mechanism in evolution that enables populations to be better adapted to their environment, allowing them to survive and reproduce. In this unit, you will study mechanisms of evolutionary change and supporting evidence. One of the main highlights of this unit is exploring the Hardy-Weinberg principle of equilibrium and using it to make predictions about a population. You will also learn to calculate and evaluate the evolution of a population, or the lack thereof, from allele frequencies.
The big ideas explored in this unit:
- Big Idea 1: Evolution – Defend the theory of evolution in scientific terms and discuss the conditions that could possibly make a population less or more likely to evolve.
- Big Idea 4: Systems Interactions – Identify how species interactions can either hamper or encourage evolution.
| Topic | Objective | Suggested Science Practice |
|---|---|---|
| 7.1 Introduction to Natural Selection | Learn the causes of natural selection. Learn how natural selection affects populations. | 2. Visual Representations |
| 7.2 Natural Selection | Learn about phenotypic variation in a population and explain its importance. | 1. Concept Explanation |
| 7.3 Artificial Selection | Learn how artificial selection plays a role in affecting population diversity. Learn about convergent evolution and explain the relationship between environmental changes and evolutionary changes. | 4. Representing and Describing Data |
| 7.4 Population Genetics | Learn how random occurrences drive evolution. Learn to explain how random processes affect the evolution of specific populations. Describe how mutations change the genetic makeup of a population over time. | 3. Questions and Methods |
| 7.5 Hardy-Weinberg Equilibrium | Using the Hardy-Weinberg model, learn to describe the conditions under which allele and genotype frequencies change. Test and explain how populations can be impacted if the conditions of the Hardy-Weinberg model are not met. | 5. Statistical Tests and Data Analysis 1. Concept Explanation |
| 7.6 Evidence of Evolution | Learn how scientific data from various disciplines are used to provide evidence for evolution. Learn about morphological, biochemical, and geological data and use them to gather evidence for evolution. Describe the fundamental molecular and cellular features and processes that are shared and conserved across organisms. Explain how it can be used as evidence for | 4. Representing and Describing Data |
| 7.7 Common Ancestry | Learn about eukaryotes’ common structural and functional features and use these as evidence to support common ancestry. | 6. Argumentation |
| 7.8 Continuing Evolution | Learn to explain how populations of organisms are subject to continued evolution. | 3. Questions and Methods |
| 7.9 Phylogeny | Learn about the types of evidence that can be used to showcase evolutionary relationships. Learn how to use and explain phylogenetic trees and cladograms to illustrate evolutionary relatedness. | 2. Visual Representations |
| 7.10 Speciation | Learn to describe the conditions under which speciation may occur. Learn to describe how ecological conditions can affect the rate of speciation. Learn about the processes and mechanisms that influence speciation. | 6. Argumentation 2. Visual Representations |
| 7.11 Extinction | Learn to describe the factors that lead to population extinction. Explain how changes in ecosystems can cause the extinction of populations. Learn about the effect of diversity in an ecosystem on the rate of speciation and extinction. Learn how extinction leads to the creation of new environments for adaptive radiation. | 3. Questions and Methods |
| 7.12 Variations in Populations | Learn to explain the relationship between genetic diversity and population dynamics with respect to environmental changes. | 6. Argumentation |
| 7.13 Origin of Life on Earth | Learn about the various scientific evidence that can be provided to justify the origin of life on Earth. | 3. Questions and Methods |
To learn more about this unit, check out AP Biology Unit 7 – Natural Selection.
Unit 8 – Ecology
(10–15% Exam Weighting | 18–21 Class Periods)
This is the last unit in the AP Biology course outline. Unit 8 deals with ecology and breaks down how biological systems are all dependent upon each other. It showcases the relationship between systems’ interactions, the availability of energy within a system, and a system’s ability to evolve and respond to environmental changes. You will study how increased biodiversity in an ecosystem is essential to its survival and what could happen if there are disruptions within biological systems.
The big ideas explored in this unit:
- Big Idea 1: Evolution – Biodiversity is essential to the survival and evolution of the species within that ecosystem.
- Big Idea 2: Energetics – The relationship between energy and a biological system’s health.
- Big Idea 3: Information Storage and Transmission – The effect of disruptions in a biological system on the storage and transmission of genetic information.
- Big Idea 4: Systems Interactions – The effect of interactions among species on the survival of an ecosystem.
| Topics | Objective | Suggested Science Practice |
|---|---|---|
| 8.1 Responses to the Environment | Learn how organisms respond to changes in their environment, both internal and external, and explain these physiological or behavioral changes. Learn how organisms respond to communication and explain how their fitness is key to the success of a population. | 3. Question and Methods |
| 8.2 Energy Flow Through Ecosystems | Learn how organisms acquire, use, and store energy. Predict what changes might occur within populations and ecosystems with respect to energy availability. Learn the importance of autotrophs and heterotrophs in relation to energy flow in an ecosystem. | 6. Argumentation |
| 8.3 Population Ecology | Describe what factors affect population growth dynamics. | 4. Representing and Describing Data |
| 8.4 Effect of Density of Populations | Learn to use population density equations to determine how populations are affected by resource availability. | 5. Statistical Tests and Data Analysis |
| 8.5 Community Ecology | Learn how to describe the structure of a community in relation to species composition and diversity. Show how interactions between populations affect community structure. Study how availability of energy within an environment is directly related to community structure. | 5. Statistical Tests and Data Analysis |
| 8.6 Biodiversity | Learn how ecosystem diversity promotes resilience in the face of environmental changes. Explain how adding or removing any component in an ecosystem could affect the community structure. | 6. Argumentation |
| 8.7 Disruptions to Ecosystems | Study adaptations and mutations and explain how they are caused by interactions between the environment and genetic variation in populations. Study and explain how the intentional or unintentional introduction of invasive species can affect ecosystem dynamics. Learn how human activities affect the structure of the ecosystem and its dynamics. Learn how geological and meteorological activity affects the structure of the ecosystem and its dynamics. | 5. Statistical Tests and Data Analysis |
Looking for a more detailed study of this unit and its topics? Then read our guide on AP Biology Unit 8 – Ecology.
These AP Biology units and topics should give you an excellent foundation for more advanced studies in biology when you get to college. They are structured to enable easy and interactive learning, so don’t fret over their vastness. Now that we’ve gone through the AP Biology concepts at a glance, let’s also look at the laboratory curriculum set for this course.
AP Biology Labs: An Outline
The AP Biology labs were introduced in 1989 and have since been an excellent way for students to formulate scientific questions, perform experiments, and discuss various topics covered in the course. There are a total of 13 labs in the curriculum, and these may include experiments on artificial selection, diffusion and osmosis, cell division, photosynthesis, cellular respiration, and energy dynamics. Different AP Biology teachers may vary the experiments but the core concepts that will be taught are the same and will help improve your skills in scientific reasoning and analysis. These labs aim to:- Help you master the subject matter
- Develop the aptitude for scientific reasoning
- Understand the empirical work
- Help you develop practical skills
- Teach you the nature of science
- Drive your interest in scientific learning
- Develop your teamwork skills
Frequently Asked Questions
What are some of the common themes of AP Biology?
What are the most important topics in AP Biology?
Below is a list of the most important AP Biology topics based on their weighting on the exam:
- (13–20%) Unit 7: Natural Selection
- (12–16%) Unit 3: Cellular Energetics & Unit 6: Gene Expression and Regulation
- (10–15%) Unit 4: Cell Communication and Cell Cycle & Unit 8: Ecology
- (10–13%) Unit 2: Cell Structure and Function
- (8–11%) Unit 1: Chemistry of Life & Unit 5: Heredity
Can I take AP Biology without taking regular biology?
Taking high school biology is a prerequisite for taking AP Biology. So, you would need to study regular biology in order to take up AP Biology.
Is AP Biology an easy course?
AP Biology is one of the easier AP Science courses. However, it also depends on your aptitude for studying biology, the amount of time you can dedicate to studying, etc.
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